Cars on fire after a driver crashed in a Bentleigh carpark. Photo: Courtesy Channel 7

All three cars caught fire and then the fire spread to a fourth, said MFB operations commander Rob Dean.

Mr Dean said the elderly man, who he said was in his 70s, would have "certainly" died had he not been rescued by a passing delivery man.

"A gentleman delivering goods to shops nearby saw the pandemonium and rushed across and dragged the elderly guy out of the vehicle. He was trapped by the leg and he dragged him out while the vehicle was on fire," said Mr Dean.

"Most certainly if he hadn't been dragged out of the vehicle he would have died."